• Journal of Nutrition and Health
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• v.54 no.2
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• pp.199-210
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• 2021

Purpose: This study investigated the food consumption behaviors in Korean adults, according to the agrifood consumer competency index (ACCI). Methods: Data obtained from the 2019 Consumption Behaviors Survey for Food were analyzed. A total of 6,176 adults (2,783 males, 3,393 females) aged ≥ 19 years, were included in the study. Based on the score of agrifood consumer competency index, the subjects were classified into three groups. The dietary habits, eating-out and food-delivery/take-out behaviors, opinion of food labeling, and concerns for domestic products were compared among the 3 groups. Results: The ACCI scores of the male and female subjects were 63.6 and 64.8, respectively. Subjects of both genders in the highest tertile of the ACCI were more likely to have a higher education level and higher health concerns, as compared to subjects in the lowest tertile (p < 0.05). Male subjects having highest tertile of the ACCI reported significantly more exercise and alcohol consumption, as compared to subjects in the lowest tertile (p < 0.05). A higher score of the ACCI also portrayed a higher satisfaction in own diet and greater checking of the food label. Moreover, subjects with a higher score of the ACCI showed greater satisfaction and reliability in the food label, as well as increased concerns for domestic agrifoods, local foods, and eco-friendly foods. Subjects in the lowest tertile of the ACCI acquired their dietary information from acquaintances, whereas subjects in the highest tertile of the ACCI learnt the information from food labels themselves. Conclusion: These results are indicative of the food consumption and behaviors of Korean adults according to their ACCI scores, and provide basic data that will be useful for implementing an effective food policy.

• Journal of Nutrition and Health
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• v.55 no.1
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• pp.155-173
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• 2022

Purpose: This study was undertaken to update the Nutrition Quotient for Elderly (NQ-E), which reflects dietary quality and behavior among Korean older adults. Methods: The first 29 items of the measurable food behavior checklist were obtained from a previous NQ-E checklist, recent literature reviews, and national nutrition policies and recommendations. One-hundred subjects (50 men and 50 women) aged ≥ 65 years living in the Seoul Metropolitan Area, including Gyeonggi Province, completed a pilot survey from March to April 2021. Based on the results of the pilot study, we conducted factor analysis and frequency analysis to determine whether the items of the survey were properly organized and whether the distribution of answers for each evaluation item was properly distributed. As a result, we reduced the number of items on the food behavior checklist and used 23 items for the national survey. Nationwide, 1,000 subjects (472 men and 528 women) aged > 65 years, completed the checklist survey, which was applied using a face-to-face survey method from May to August 2021. The construct validity of the NQ-E 2021 was assessed using confirmatory factor analysis, LISREL. Results: Seventeen food behavior checklist items were selected for the final NQ-E 2021. Checklist items addressed three factors: balance (8 items), moderation (2 items), and practice (7 items). Standardized path coefficients were used as the weights of items to determine nutrition quotients. NQ-E and three-factor scores were calculated according to the weights of questionnaire items. Conclusion: The updated NQ-E 2021 produced by structural equation modelling provides a suitable tool for assessing the dietary quality and behavior of Korean older adults.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.2
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• pp.61-72
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• 2022

The present study was conducted to examine the effect of soybean silage as a crude protein supplement for corn silage in the diet of Hanwoo steers. The first experiment was conducted to evaluate the effect of replacing corn silage with soybean silage at different levels on rumen fermentation characteristics in vitro. Commercially-purchased corn silage was replaced with 0, 4, 8, or 12% of soybean silage. Half gram of the substrate was added to 50 mL of buffer and rumen fluid from Hanwoo cows, and then incubated at 39℃ for 0, 3, 6, 12, 24, and 48 h. At 24 h, the pH of the control (corn silage only) was lower (p<0.05) than that of soybean-supplemented silages, and the pH numerically increased along with increasing proportions of soybean silage. Other rumen parameters, including gas production, ammonia nitrogen, and total volatile fatty acids, were variable. However, they tended to increase with increasing proportions of soybean silage. In the second experiment, 60 Hanwoo steers were allocated to one of three dietary treatments, namely, CON (concentrate with Italian ryegrass), CS (concentrate with corn silage), CS4% (concentrate with corn silage and 4% of soybean silage). Animals were offered experimental diets for 110 days during the growing period and then finished with typified beef diets that were commercially available to evaluate the effect of soybean silage on animal performance and meat quality. With the soybean silage, the weight gain and feed efficiency of the animal were more significant than those of the other treatments during the growing period (p<0.05). However, the dietary treatments had little effect on meat quality except for meat color. In conclusion, corn silage mixed with soybean silage even at a lower level provided a greater ruminal environment and animal performances, particularly with increased carcass weight and feed efficiency during growing period.

• Journal of Nutrition and Health
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• v.55 no.2
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• pp.296-308
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• 2022

Purpose: To investigate the effect of a mother's modeling and feeding practices on the eating behavior of the children. Methods: From April to June 2018, 1,036 young children aged 2 to 6 years and their mothers in Gyeongsan, Gyeongsangbuk-do, were examined for their eating behavior and feeding practices using a verified dietary behavior test (DBT). The children's dietary behavior was classified into four categories: "access evasiveness", "sensory acuity", "hyperactivity", and "irregularity". The mother's eating behavior was classified into three categories: "pickiness", "negligence", and "irregularity", and feeding practice types were classified into two categories: "responsibility/monitoring", and "restriction/pressure". The differences between the groups were tested using the t-test, ANOVA, and Duncan's multiple range test. The influence of feeding practices on the children's eating behavior was analyzed by hierarchical regression analysis while controlling for the mother's modeling. Results: The problem rates of irregularity, negligence and pickiness in the mother's modeling were 33.7%, 22.8%, and 20.7%, respectively. An analysis of the mother's feeding practices revealed that responsibility/monitoring had a middle, high and low significance in 74.2%, 17.3%, and 8.5% of respondents, respectively and the risk rate of restriction/pressure when guiding children to eat was 15.3%. The problem rates for sensory acuity, access evasiveness, irregularity, and hyperactivity in children were 27.9%, 26.1%, 24.8%, and 22.0%, respectively. Among the four eating behavior characteristics of children, the child's access evasiveness and sensory acuity were more affected by their pickiness rather than the mother's feeding practices, and the child's hyperactivity was more influenced by feeding practices than the mother's eating behavior. The child's irregularity was similarly affected by the mother's eating behavior and feeding practices. Conclusion: Since the mother's eating behavior and feeding practices affect the children's eating behavior, a diet improvement program for children should consider not only the nutrition education of children but also the mother's eating behavior and provide the necessary intervention for feeding practices.

• Korean Journal of Poultry Science
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• v.48 no.2
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• pp.91-100
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• 2021

The study determined the effects of stock density (SD) and energy level (EL) on growth performance, serum biochemistry, and meat quality in Korean native chickens. A total of 240 chickens were randomly assigned to one of the four treatments including two stock density (low, 14, and high, 16 chickens per m²) and two energy level (low, 2,950, 3,000, 3050 ME kcal/kg, and high 3,150, 3,200, 3,250 ME kcal/kg, for starter, grower, and finisher, respectively). During the whole period of the experiment, the chickens were fed ad libitum. The greater final body weight and weight gain were achieved in chickens fed high energy diet, whereas the final body weight and weight gain were significantly reduced in high-density treatment compared with the low density. Chickens in low-density groups had a higher feed intake compared with high-density treatment, however, the energy level did not affect the feed intake. An improved overall feed conversion ratio was detected in the high energy treatment. There was a significant interaction between stock density and energy level on cholesterol concentration. The concentration of aspartate transaminase in serum was increased by higher stock density. There was a significant treatment interaction on IgM levels. Moreover, the carcass rate was significantly increased in the high energy level treatment. Based on the findings, we suggest that rearing chickens in low density with high dietary energy levels could be beneficial by improving the growth performance.

• Journal of Korean Home Economics Education Association
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• v.33 no.2
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• pp.135-152
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• 2021

The purpose of this study was to examine the effectiveness of the curriculum implementation of 「Food Safety and Health」, a Home Economics elective course, for high school students. Accordingly, several units of the 「Food Safety and Health」curriculum were piloted in six high schools in Chungbuk, Gyeonggi, Daejeon, and Sejong, and 1,199 questionnaires collected from students who participated in the classes were analyzed. The results are as follows. The 「Food Safety and Health」class had a significant effect on improving the total score of 'food safety and health' knowledge of high school students and scores for sub-dimensional area. Compared to the pre-test, the overall rate of correct answers for the post-test has increased by 7.99%p, and schools that implemented the relevant unit class relatively more had higher improvement scores. In addition, the 「Food Safety and Health」class has positively changed the eating behavior of high school students, and had a significant effect on having a habit of eating a variety of foods evenly. High school students who participated in the 「Food Safety and Health」class evaluated their classes very positively (4.27 out of 5 points), and responded that the content of the class was interesting, easy to understand, and helpful for their diet in daily life. According to the responses to the open-ended questions, students responded that the class was helpful in acquiring food-related knowledge in their real lives, while there were so many limitations for experiencing lab class and group activities due to COVID 19. In preparation for the high school credit system, this study is meaningful that it has expanded the elective courses in home economics area, as well as the right to choose subjects for high school students.

• Korean Journal of Poultry Science
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• v.49 no.4
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• pp.181-188
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• 2022

This study was conducted to investigate the effects of the metabolic energy levels of Korean native chicken breeder diets on laying performance, egg quality, fertility and hatchability. On the basis of dietary metabolic energy values (2,800, 2,700, and 2,650 kcal/kg), 168 twenty-week-old 'Woorimatdag' breeders (maternal line) were divided into three treatment groups (four replications per treatment with each replicate containing 14 birds) and reared until 32 weeks of age. We found that the body weight of hens increased with age, although there were no significant differences among treatments with respect to body weight or egg weight. Egg production ratio at 20-24 and 24-28 weeks of age tended to be low in birds fed the 2,700 and 2,650 kcal/kg diets, although the differences among treatments were none significant. Feed intakes was significantly decreased as the metabolic energy level reduced (P<0.05). There were no significant differences among treatments with respect to feed conversion ratio or the strength and thickness of eggshell. Similarly, we detected no significant differences among the three metabolic energy levels with regards to fertility, hatchability, or chick weight. In conclusion, our findings indicate that during the initial phase of laying, the metabolic energy level of 'Woorimatdag' breeder diets could be lowered to 2,700 kcal/kg without significantly influencing the laying performance of breeders or egg quality, fertility and hatchability, and chick weight.

• Journal of Nutrition and Health
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• v.55 no.3
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• pp.359-375
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• 2022

Purpose: Adult Korean men belonging to the main economically active population are known to have long sedentary hours. This study was undertaken to determine the difference and relevance of sedentary hours on the nutrition, diet, and health status of adult men, and to suggest how to prevent health risk factors. Methods: Subjects (n = 1,068) were classified into 4 groups based on their sedentary hours, ranging from the first quartile (Q1) having the least hours spent sitting, to the fourth quartile (Q4) spending the longest hours. Results: Subjects belonging to Q4 had the lowest average age, the largest waist circumference, and the highest level of education. Among those engaged in economic activities, the ratio of white-collar workers was significantly higher in Q4. Accordingly, the rate of not doing high-intensity or moderate-intensity physical activity while working was also the highest in Q4. A significant difference was obtained in the drinking frequency between groups, but this was found to be associated with the average working hours rather than sedentary hours. The proportion of not doing aerobic exercise was higher with longer sitting hours. The highest diagnosis of diabetes (8.8%) was obtained in the Q4 group. Among the factors related to cardiovascular disease, only low density lipoprotein-cholesterol showed a significant difference, with Q4 being significantly higher than Q1. Considering energy and nutrient intake, vitamin B₁ and calcium intake were the lowest in the group with the longest sitting hours, as well as the least consumption of vitamin C than the recommended estimated average requirement. Conclusion: The results of this study suggest that the health and nutritional status of Korean adult men are affected by sedentary hours. This should be recognized as a health risk factor and guidelines need to be developed for sedentary lifestyle management.

• Journal of Nutrition and Health
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• v.55 no.3
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• pp.376-389
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• 2022

Purpose: Obesity can lead to several chronic diseases. With a continuous increase in the obesity rates, sustainable healthy weight management among growing adolescents has become essential. This study was conducted to examine the relationship between obesity-related factors and creative convergence ability. This could form the basis for convergence education for the sustainable healthy weight management of adolescents. Methods: Data were collected from 430 adolescents in Daegu, Gyeongbuk, and Gyeonggi regions using a self-administered 5-Likert questionnaire from November to December 2020. Results: The average score of the male students was higher than that of the female students in terms of healthy weight management convergence awareness, creativity, convergence thinking ability, self-efficacy, exercise, and dietary diversity. On the other hand, the dietary restraint score and the number of weight loss attempts were higher in the female students. Dietary restraint, disinhibition scores and weight loss attempts were higher in obese adolescents compared to underweight adolescents. It was found that dietary restraint, convergence thinking ability, problem-solving ability, exercise, and dietary diversity factors had a positive effect on healthy weight management convergence awareness. Healthy weight management convergence awareness, exercise, meal amount management, junk food management, weight loss belief, and weight loss trial experience had a positive effect on dietary restraint. Convergence thinking ability, weight loss experience, and obesity factors had a positive effect on dietary disinhibition. Conclusion: The sustainable healthy weight management education of adolescents is based on weight management knowledge and awareness of convergence, and must include gender differences. Thus, the problem-solving ability for healthy weight management can be creatively cultivated to enhance self-efficacy.

• Journal of Nutrition and Health
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• v.55 no.2
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• pp.211-226
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• 2022

Choline, an essential nutrient for humans, is required for the structural integrity of the cell membranes, methyl-group metabolism, synthesis of the neurotransmitter acetylcholine, synthesis of the membrane phospholipid components of the cell membranes, and the transport of lipids and cholesterol. Choline can be synthesized in the body, but it is insufficient to meet the daily requirements and hence it must be obtained through the diet. In the United States/Canada, Australia/New Zealand, Europe, China, and Taiwan, the adequate intake (AI) and tolerable upper intake level (UL) of choline have been established, while the establishment of the 2020 Dietary Reference Intakes for Koreans (KDRI) for choline was postponed due to the lack of a choline database for Korean foods and studies on the choline intake of Koreans. However, as part of the preparation work for the 2020 DRI revision and finalization, choline intake and the possibility of disease occurrence were verified through analysis of published data. The groundwork for the subsequent establishment of a choline DRI was laid through a literature search, evaluation, and review of the literature reported from 1949 up to 2019. This can be regarded as the culmination of this project. According to the results of randomized controlled trials (RCTs), cohort studies, case-control studies, and cross-sectional observational studies in humans, approximately 400-500 mg/day of choline intake was effective in preventing liver function damage (fatty liver), neural tube damage, cardiovascular disease, breast cancer, and cognitive function improvement. The same amount of choline intake, however, also correlated with the risk of prostate and colorectal cancer. At present, there is limited information available on choline intake and health outcomes, particularly for the Korean population. More human studies, including clinical trials on the requirements and the physiological benefits associated with dietary intake, are needed to establish the KDRI for choline.